I am well aware they need to be charged/dis-charged properly to avoid damage and explosions.

To my knowledge a charging system has two components which are the managed charging and cut-off once charged and discharge protection when the batteries voltage drops.

I found a board that uses the common TP4056 controller to charge the lithium battery and cut-off once charged. It also has discharge protection at 2.5V.

I have two questions:

l So this means I can hook up the above (or any) Lithium batteries to the charging board as well as my device and it would run well from the batteries until they got too low, at which the board would cut off the supply to the device leaving the device isolated from the batteries until charged again.

l It says the discharge protection is at 2.5V isn't this well below the safe discharge voltage of a lithium cell. I thought you should never go below 3V?

I apologize if this question is rudimentary however I'd like to make sure when dealing with constant use of lithium batteries.